Website canonicalization is the practice of ensuring that every unique topic exists only in one page in your website. This is to ensure that there are no confusions when search engines categorize and rank your content. Search engines are picky with duplicate content which may end up getting unindexed.
If duplicating your content cannot be avoided, for example redundant content is used to emphasize a point, then the link rel=canonical tag may come in handy. For example, you can place the following entry in the header section the duplicated page:
This would tell search engines that the page is a copy of http://pr.web-backlinks.com/ and all the relevance for the topic in question should flow back to that URL.
